/Engine/Source/Developer/MessageLog/Public/Model/MessageLogListingModel.h
Replaces the message at the given index
int32 ReplaceMessage ( const [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [FTokenizedMessage](API\Runtime\Core\Logging\FTokenizedMessage) > & NewMessage, const uint32 PageIndex, const int32 MessageIndex )